Andrew w



N0. 62l,|0|.' Pafented Mar. I4, I899,

. A. W. K'NUX.

GRIPPER ATTACHMENT FOB PLATEN PRINTING PRESSES. (Application mm. as. 1597. Renewed Aug. a, 1:398.

(No Model.)

Fl E-II.

( b Pl 1?? :1 9. hr A U I I) X g J a INVENTORZ WITNESSES I By 7i 5 J .dttorney. I

NITED STATES PATENT Fries.

=ANDRElV W. KNOX, OF NEYV YORK, N. Y.

SPEGIFICATION forming part of Letters Patent No. 621,101, dated March 14, 1899.

Application filed MarchZS, 1e97, Renewed August 8,1898. Serial No. 688,128. (No model.)

To all whom it may concern:

Be it known that I, ANDREW W. KNOX, a citizen of the United States, residing in the city, county, and State of New York, have invented certain new and useful Improvements in Gripper Attachments for Platen Printing Presses, of which the following is a specification.

This invention relates to the class of devices employed on platen printing-presses for stripping the sheet from the form as the platen withdraws after the impression, such devices being commonlycalled grippers. Usually such grippers are simple bars, two in number, arranged to take behind the blank portion or margin of the sheet at the respective sides. Such bars must, of course, be adjusted laterally of the platen to suit sheets and typeforms of different widths, and this setting of the bars for each job requires considerable time. Moreover, there are some jobs where it is not easy to employ such grippers satisfactorily at all. Some forms of such grippers have short fingers on the bar to project in and take over the side margin of the sheet, and in some cases a flexible cord has been stretched across from one gripper to the other. None of these attains what I seek to accomplish by my invention, which will now be described with reference to the accompanying drawings, which illustrate an embodiment thereof.

Figure 1 is a plan view, on a small scale, of a platen having my improved grippers applied thereto. Fig. 2 is a perspective View of the clamp for securing the tie band or strip adjustably to the gripper-bar. Fig. 3 is a transverse section of the clamp, and Fig. 4 is a longitudinal section thereof. Fig. 5 is a view showing the gripper-bar both in edge View and plan.

In Fig. 1 X represents the platen of an ordinary printing-press, and a; a sheet placed thereon up to the usual gage-pins. Z is the slotted plate, to which the gripper-bars A A are secured by a bolt engaging the slot in said plate in the usual way. In order to lighten the gripper-bar, it is or may be cut away to narrow its ,main portion, the attaching end only being of the usual breadth. A longitudinal channel a is formed in one face of the bar, which I will call for convenience the upper face.

' B B are clamps on the respective bars A for holding a band or strip 0, which ties the two bars together and takes under the upper end margin of the sheet w during the impression and strips or detaches it from the form.

The band or strip 0 is preferably of thin but rather stiff metal secured adjustably in the clamps B at its respective ends. It'alone takes under the sheet, the bars A being set wider-apartthan the width of the sheet.

The construction of the clamp 13 is well illustrated in Figs. 2, 3, and 4. It comprises, as here shown, an oblong metal block b, with a transverse recess or gain in its under side to receive the bar A and longitudinal dovetail or undercut grooves in the lower faces of its ends to receive the tie-band O, which is beveled or shaped to fit snugly in said grooves. Secured to the block him the transverse recess formed therein is a plate I), which fits into the channel a of the bar A. Through this plate is driven a milled headed screw b the tip of which impinges onthe bar A in the bottom of the channel a when the screw is driven down.

To assemble the parts, the block b is placed on the bar A so that the latter engages the recess in the block and the plate I) engages the channel in the bar. The band or strip 0 is now inserted in the dovetail grooves in the block, the proportions being such that when in said grooves it fits up snugly to the lower face of the bar, as clearly seen in Figs. 3 and 4, thus locking the block to the bar, but leaving it free to play along the bar. When the band is properly inserted in theclamps and the latter are adjusted along the respective bars, the screws 19 are driven down, so as to draw the band up snugly against the bar and secure both band and clamps in place on the bars.

It will be noted that the use of the tie-band C avoids the necessity of shifting the bars A laterally throughout a great range of work and provides a stripper which takes under the upper margin of the sheet throughout its entire width. This is important, as being the proper point to take under the sheet for detaching it from the form. The lower end of the sheet takes under the lips of the gage-pins,

vices, and the band 0 takes under the upper margin of the sheet, as described. Another advantage of the tie-band is that it holds the bars A in place and prevents them from shifting laterally, as they are liable to do if they become loosened at their lower ends.

In Fig. 1 the tie-band O is represented as resting or extending over the sheet as; but it will be understood that during the impression it will be underthe sheet or between the sheet and the bed on which the type-form rests, as in all gripping devices for the purpose of detaching the sheet from the form when the platen draws back. The strip or band Omay be made from any strong, tough, and stiff material. Metal is preferred.

My device may be applied to any of the ordinary platen-presses.

Of course the use of the tie-band C does not prevent the bars A, one or both, from being made to take beneath or behind the side margin or margins of the sheet.

Having thus described my invention, I claim 1. A gripper attachment for a plat-en printing-press, co mprising two laterally-adj ustable gripper-bars adapted in all positions to bear on the face of the platen when the impression is made, and a tie band or strip 0, of stiff material extending across the platen from one of said bars to the other and secured adjustably to the latter, whereby the strip may be set at diiferent points along the bars, substantially as set forth.

2. A gripper attachment for a platen printi n g-press, com prising two laterall y-ad j us table gripper-bars adapted in all positions to bear on the face of the platen when theimpression is made, a tie band or strip 0, of stilt material extending across the platen from one of said bars to the other, said strip having beveled edges, and clamps on said bars having keeper-grooves to receive said tie-band and secure the strip to said bars in a manner to' permit the latter to be moved both transversely and longitudinally over the bars, substantially as set forth.

4. In a gripper attachment, the combination with the gripper-bars A A, each having a longitudinal recess or channel in its face, and the tie band or strip 0, beveled at its edges, of the clamps B, each comprising a block b, recessed on one face to fit over the gripper-bar and having an undercut groove at right angles to the bar to receive the tiebancl, a plate I), secured to the block in said recess, and a screw D which screws through said plate and bears on the bar, substantially as set forth.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

, ANDRE\V \V. KNOX.

lVitnesses:

HENRY CONNETT,

PETER A. Ross. 

